builder: when stream is empty, the builder crashes given it does not block waiting for work

[filipecosta90]

root@hpe10:~# redis-benchmarks-spec-builder 
2021-08-19 14:32:20 INFO Using package dir /usr/local/lib/python3.6/dist-packages/redis_benchmarks_specification/setups/builders for inner file paths
2021-08-19 14:32:20 INFO Using the following build specs folder /usr/local/lib/python3.6/dist-packages/redis_benchmarks_specification/setups/builders, containing 4 different specs.
2021-08-19 14:32:20 INFO Using redis available at: 34.194.187.44:12010 to read the event streams
2021-08-19 14:32:20 INFO checking build spec requirements
2021-08-19 14:32:20 INFO Build icc-2021.3.0-amd64-ubuntu18.04-default requirement: checking build image intel/oneapi-hpckit:2021.3-devel-ubuntu18.04 is available.
2021-08-19 14:32:20 INFO Build icc-2021.3.0-amd64-ubuntu18.04-default requirement: build image intel/oneapi-hpckit:2021.3-devel-ubuntu18.04 is not available locally. Fetching it from hub
2021-08-19 14:32:21 INFO Build gcc:8.5.0-amd64-debian-buster-default requirement: checking build image gcc:8.5.0-buster is available.
2021-08-19 14:32:21 INFO Build gcc:8.5.0-amd64-debian-buster-default requirement: build image gcc:8.5.0-buster is not available locally. Fetching it from hub
2021-08-19 14:32:23 INFO Build icc-2021.3.0-amd64-ubuntu18.04-monotonic-clock requirement: build image intel/oneapi-hpckit:2021.3-devel-ubuntu18.04 availability was already checked.
2021-08-19 14:32:23 INFO Build icc-2021.3.0-amd64-ubuntu18.04-libc requirement: build image intel/oneapi-hpckit:2021.3-devel-ubuntu18.04 availability was already checked.
2021-08-19 14:32:23 INFO Consumer group named builders-cg:redis/redis/commits already existed.
2021-08-19 14:32:23 INFO Entering blocking read waiting for work.
Traceback (most recent call last):
  File "/usr/local/bin/redis-benchmarks-spec-builder", line 8, in <module>
    sys.exit(main())
  File "/usr/local/lib/python3.6/dist-packages/redis_benchmarks_specification/__builder__/builder.py", line 119, in main
    builders_folder, conn, different_build_specs, previous_id
  File "/usr/local/lib/python3.6/dist-packages/redis_benchmarks_specification/__builder__/builder.py", line 154, in builder_process_stream
    if len(newTestInfo[0]) < 2 or len(newTestInfo[0][1]) < 1:
IndexError: list index out of range